How to create multicast on Kotlin/Native for ios/macos target

Question

As the title says, in Swift, adding import Network can use NWMulticastGroup to create multicast, but Kotlin/Native for ios/macos still cannot use NWMulticastGroup after import platform.Network.* in src/appleMain. What is preventing me from using NWMulticastGroup? Or is this use case not currently supported? Thank you!

Other information:

• kotlin: 2.0.0

• gradle: 8.8

• host: macOS 14.4.1

• build.gradle.kts:

  plugins {
      alias(libs.plugins.kotlin.multiplatform) // version "2.0.0"
  }
  
  kotlin {
      listOf(
          iosX64(),
          iosArm64(),
          iosSimulatorArm64(),
  
          macosArm64(),
          macosX64(),
      ).forEach { target ->
          target.binaries.framework {
              baseName = "shared"
              isStatic = true
          }
      }
  
      sourceSets {
          commonMain.dependencies {
              implementation(libs.kotlin.coroutines)
          }
      }
  }
  

Answer 1

NWMulticastGroup is written in Swift, and Kotlin cannot interoperate with Swift yet.

In other words, in Kotlin, you can only use the parts of Network.framework that are exposed to (Objective-)C. For example, instead of creating a NWMulticastGroup, you would need to call nw_group_descriptor_create_multicast. See the Objective-C version of the Network.framework documentation for more info. From a brief look, the APIs available to Kotlin mostly have a one-to-one correspondence with the Swift APIs - it's just that the former is a lot more "C-like".

I also found this post, which shows the Objective-C version of some Swift code using Network.framework. This may be helpful too.